The prior patents are directed to a flow-through capacitor and the use of the flow-through capacitor in a controlled charge chromatographic column and system and to a method of operation of the flow-through capacitor and chromatographic system, all directed to the purification of liquids. In one embodiment, the flow-through capacitor comprises a spirally-wound flow-through capacitor comprising a plurality of adjacent layers, and typically, wound about a porous, nonconductive tube and containing anode and cathode leads adapted to be connected to a DC power supply to provide for activation of the anode and cathode. In another embodiment, the invention is directed to a flow-through capacitor in a stacked column form about a central porous nonconductive tube and also for use in a chromatographic column and system for the purification of liquids. Both the spirally-wound and the stacked column flow-through capacitors are adapted to be placed within a housing with an inlet for the introduction of a liquid to be purified and an outlet for the discharge of a purified liquid and a concentrated liquid.
The flow-through capacitor comprises: a plurality of adjacent, alternative layers of a spacer layer comprising a non-electrically conductive, ion-porous spacer, such as nylon cloth, to permit the flow of liquid therethrough; an electrically conductive backing layer, such as graphite foil, and a high surface area layer on the conductive backing layer comprising a high surface area, electrically conductive layer, such as activated carbon, to act as the stationary phase, for example, of a chromatographic column. As disclosed, a plurality of the layers are first and second spacer layers, backing layers and surface area layers arranged in a spiral or a stacked column form housing and then anode and cathode leads connected, e.g. integrally and respectively, to the first and second backing layers, and to a DC power source to provide separate and opposite electrical charges on the backing layers and on the high surface area layers. The fluid is passed through the flow-through capacitor, such as, for example, an aqueous salt solution, to provide for the recovery of a concentrated salt and a purified liquid.
It is desirable to provide for a new and improved flow-through capacitor, chromatographic system and method to simplify the construction and manufacture of the flow-through capacitor, system and method and which provides for an increased efficiency in the purification of fluids.